<template>
  <div class="app-container">
    <h2 style="text-align: center;">发布新课程</h2>
    <el-steps :active="1" process-status="wait" align-center style="margin-bottom: 40px;">
      <el-step title="填写课程基本信息"/>
      <el-step title="创建课程大纲"/>
      <el-step title="提交审核"/>
    </el-steps>

    <el-form label-width="120px">
      <el-form-item label="课程标题">
        <el-input v-model="courseInfo.title" placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"/>
      </el-form-item>
      <!-- 课程分类 -->
      <el-form-item label="课程分类">
        <el-select
          v-model="courseInfo.subjectParentId"
          placeholder="一级分类"
          @change="getTwoSubject(courseInfo.subjectParentId)"
        >
          <el-option
            v-for="subject in subjecOnetList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
        <el-select
          v-model="courseInfo.subjectId"
          style="margin-left: 20px;"
          placeholder="二级分类">
          <el-option
            v-for="subject in subjecTwotList"
            :key="subject.id"
            :label="subject.title"
            :value="subject.id"/>
        </el-select>
      </el-form-item>
      <!-- 课程讲师 -->
      <el-form-item label="课程讲师">
        <el-select
          v-model="courseInfo.teacherId"
          placeholder="请选择">
          <el-option
            v-for="teacher in teacherList"
            :key="teacher.id"
            :label="teacher.name"
            :value="teacher.id"/>
        </el-select>
      </el-form-item>
      <el-form-item label="总课时">
        <el-input-number :min="0" v-model="courseInfo.lessonNum" controls-position="right" placeholder="请填写课程的总课时数"/>
      </el-form-item>
      <el-form-item label="课程简介">
        <tinymce :height="300" v-model="courseInfo.description"/>
      </el-form-item>
      <!-- 课程封面 -->
      <el-form-item label="课程封面">
        <el-upload
          :show-file-list="false"
          :on-success="handleAvatarSuccess"
          :before-upload="beforeAvatarUpload"
          :action="BASE_API+'/eduoss/fileoss/upload'"
          class="avatar-uploader">
          <img :src="courseInfo.cover">
          <el-button size="small" type="primary">点击上传</el-button>
          <div slot="tip" class="el-upload__tip">只能上传jpg/png文件，且不超过2mb</div>
        </el-upload>
      </el-form-item>
      <el-form-item label="课程价格">
        <el-input-number :min="0" v-model="courseInfo.price" controls-position="right" placeholder="免费课程请设置为0元"/> 元
      </el-form-item>
      <el-form-item>
        <el-button :disabled="saveBtnDisabled" type="primary" @click="saveOrUpdate">保存并下一步</el-button>
      </el-form-item>
    </el-form>
  </div>
</template>

<script>
import course from '@/api/course/course'
import teacher from "@/api/teacher/teacher"
import subject from "@/api/subject/subject"
import Tinymce from '@/components/Tinymce'

export default {
  name: "Info",
  components: {
    Tinymce
  },
  data() {
    return {
      saveBtnDisabled: false, // 保存按钮是否禁用
      courseId: '',
      courseInfo: {
        title: '',
        subjectId: '',
        subjectParentId: '',
        teacherId: '',
        lessonNum: 0,
        description: '',
        cover: '',
        price: 0
      },
      teacherList: [],
      subjecOnetList: [],
      subjecTwotList: [],
      BASE_API: process.env.BASE_API
    }
  },
  created() {
    if (this.$route.params && this.$route.params.id) {
      this.courseId = this.$route.params.id
      this.showDetailInfo()
    } else {
      this.getAllTeacher()
      this.getAllSubject()
    }
  },
  methods: {
    saveOrUpdate() {
      if (this.$route.params && this.$route.params.id) {
        this.update()
      } else {
        this.save()
      }
    },
    save() {
      course.addCourse(this.courseInfo).then(response => {
        this.$message({
          type: 'success',
          message: '保存成功!'
        })
        return response// 将响应结果传递给then
      }).then(response => {
        this.$router.push({ path: '/course/chapter/' + response.data.courseId })
      }).catch((response) => {
        this.$message({
          type: 'error',
          message: response.message
        })
      })
    },
    update() {
      this.courseInfo.id = this.courseId
      course.updateCourse(this.courseInfo).then(response => {
        this.$message({
          type: 'success',
          message: '修改成功!'
        })
        return response// 将响应结果传递给then
      }).then(response => {
        this.$router.push({ path: '/course/chapter/' + response.data.courseId })
      }).catch((response) => {
        this.$message({
          type: 'error',
          message: response.message
        })
      })
    },
    getAllTeacher() {
      teacher.getAllList().then(res => {
        this.teacherList = res.data.list
      }).catch(err => {
        this.$message({
          type: 'error',
          message: err.message
        })
      })
    },
    getAllSubject() {
      subject.getSubjectList().then(res => {
        this.subjecOnetList = res.data.list
      }).catch(err => {
        this.$message({
          type: 'error',
          message: err.message
        })
      })
    },
    getTwoSubject(pId) {
      this.courseInfo.subjectId = ""
      for (let i = 0; i < this.subjecOnetList.length; i++) {
        if (this.subjecOnetList[i].id === pId) {
          this.subjecTwotList = this.subjecOnetList[i].children
        }
      }
    },
    handleAvatarSuccess(res, file) {
      console.log(res)// 上传响应
      console.log(URL.createObjectURL(file.raw))// base64编码
      this.courseInfo.cover = res.data.url
    },
    beforeAvatarUpload(file) {
      const isJPG = file.type === 'image/jpeg'
      const isLt2M = file.size / 1024 / 1024 < 2
      if (!isJPG) {
        this.$message.error('上传头像图片只能是 JPG 格式!')
      }
      if (!isLt2M) {
        this.$message.error('上传头像图片大小不能超过 2MB!')
      }
      return isJPG && isLt2M
    },
    showDetailInfo() {
      course.getCourseDetail(this.courseId).then(res => {
        this.courseInfo = res.data.data
        subject.getSubjectList().then(res => {
          this.subjecOnetList = res.data.list
          for (let i = 0; i < this.subjecOnetList.length; i++) {
            const oneSubject = this.subjecOnetList[i]

            if (this.courseInfo.subjectParentId === oneSubject.id) {
              this.subjecTwotList = this.subjecOnetList[i].children
            }
          }
        })
        this.getAllTeacher()
      }).catch(err => {
        this.$message({
          type: 'error',
          message: err.message
        })
      })
    }
  },
  beforeRouteLeave(to, form, next) {
    this.$route.meta.keepAlive = false
    this.courseInfo = {}
    next()
  }
}
</script>

<style scoped>
  .tinymce-container {
    line-height: 29px;
  }
</style>
